Preparation of Carboxym Ethyl Chitosan

To prepare good water-solubility N,O-carboxymethyl chitosan(N,O-CMC), using chitosan as a basic reactant, chitosan is modified with chloroacetic acid in the presence of sodium hydroxide. The influence factors on the substitution degree of CMC such as the ratio of reactants,reaction temperature,reaction time,soda concentration and amount of catalyst were discussed. The result indicates that optimal reacting temperature was 50℃,its optimal reacting time was 4 h,its optimal soda concentration was 40% and its optimal catalyst was 5%.The substitution degree of product is highest.